Might be getting a carradice barley soon(for my new bike), will let you know how that is(unless it is too retro?)
Barleys a good one to start with, I use one daily for my commute and having added a shoulder strap its easy to carry at the end as well.
I used it for a 3 day tour with waterproofs strapped ontop and everything else tighly packed in the main bag.
No complaints so far, had to do some minor fettling on the stitching of the 'lights strap' to improve the stability but thats it. I use the 'Bagman QR' mechanism with mine (which I padded with an old sock and tape to improve support) whereas others use the 'SQR Uplift'. Both do the same thing which is to lift the bag away from the wheel and improve its stability.
Go for the green one, longer wait time (6 weeks for mine) but far more stylish than the bog standard black.
PS I'll add the tour was staying in a hotel, and at a friends, it didnt involve carrying a tent as well!